The overall objective of this proposal is to characterize peripheral nerve hydration by non-invasive magnetic resonance imaging in diabetic peripheral neuropathy, to correlate this structural parameter of the sural and tibial nerves with neurophysiological function, and to relate these structural and functional dimensions to the clinical symptomalogy and diabetic state. The magnetic resonance images will be obtained from the sural and tibial nerves at one centimeter level beginning one millimeter above the malleolus and extending five centimeters superior to the malleolus. The T 1 relaxation time will be calculated on an increase in the null fraction of water in the interstitial location (increase hydration) increases the composite T 1. Therefore, measurements of T 1 in diabetic patients with and without neuropathy and in normal controls will be analyzed to determine if there are changes in the composite T 1, and hence interstitial hydration in patients with neuropathy as compared to those without neuropathy. Motor sensory and reflex nerve conduction studies will be used to assess neurophysiological function of the sural and tibial nerves. Tibial nerve conduction velocities and H reflex studies will be done. In addition, nerve conduction velocities of the peroneal motor and superficial peroneal nerve will be done where indicated.